When using multi-homed machines, it's nice to be able to specify the local IP to use for outbound connections. This patch gives cifs the ability to bind to a particular IP address.
Usage: mount -t cifs -o srcaddr=192.168.1.50,user=foo, ... Usage: mount -t cifs -o srcaddr=2002::100:1,user=foo, ... Signed-off-by: Ben Greear <[email protected]> --- :100644 100644 b7431af... ac69602... M fs/cifs/cifsfs.c :100644 100644 d82f5fb... d6f0a7d... M fs/cifs/cifsfs.h :100644 100644 c9d0cfc... 784fd4a... M fs/cifs/cifsglob.h :100644 100644 ec0ea4a... c70f6f8... M fs/cifs/connect.c fs/cifs/cifsfs.c | 30 +++++++++++++++++ fs/cifs/cifsfs.h | 3 ++ fs/cifs/cifsglob.h | 1 + fs/cifs/connect.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++++++- 4 files changed, 125 insertions(+), 2 deletions(-) diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c index b7431af..ac69602 100644 --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -36,6 +36,7 @@ #include <linux/kthread.h> #include <linux/freezer.h> #include <linux/smp_lock.h> +#include <net/ipv6.h> #include "cifsfs.h" #include "cifspdu.h" #define DECLARE_GLOBALS_HERE @@ -357,6 +358,20 @@ cifs_show_address(struct seq_file *s, struct TCP_Server_Info *server) } } +bool +cifs_addr_is_specified(struct sockaddr *srcaddr) { + struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr; + struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr; + static const struct in6_addr c_in6addr_any = IN6ADDR_ANY_INIT; + switch (srcaddr->sa_family) { + case AF_INET: + return saddr4->sin_addr.s_addr != 0; + case AF_INET6: + return (!ipv6_addr_equal(&c_in6addr_any, &saddr6->sin6_addr)); + } + return false; +} + /* * cifs_show_options() is for displaying mount options in /proc/mounts. * Not all settable options are displayed but most of the important @@ -367,6 +382,8 @@ cifs_show_options(struct seq_file *s, struct vfsmount *m) { struct cifs_sb_info *cifs_sb = CIFS_SB(m->mnt_sb); struct cifsTconInfo *tcon = cifs_sb->tcon; + struct sockaddr *srcaddr; + srcaddr = (struct sockaddr *)(&tcon->ses->server->srcaddr); seq_printf(s, ",unc=%s", tcon->treeName); if (tcon->ses->userName) @@ -374,6 +391,19 @@ cifs_show_options(struct seq_file *s, struct vfsmount *m) if (tcon->ses->domainName) seq_printf(s, ",domain=%s", tcon->ses->domainName); + if (cifs_addr_is_specified(srcaddr)) { + struct sockaddr_in *saddr4; + struct sockaddr_in6 *saddr6; + saddr4 = (struct sockaddr_in *)srcaddr; + saddr6 = (struct sockaddr_in6 *)srcaddr; + if (saddr6->sin6_family == AF_INET6) + seq_printf(s, ",srcaddr=%pI6c", + &saddr6->sin6_addr); + else + seq_printf(s, ",srcaddr=%pI4", + &saddr4->sin_addr.s_addr); + } + seq_printf(s, ",uid=%d", cifs_sb->mnt_uid); if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_UID) seq_printf(s, ",forceuid"); diff --git a/fs/cifs/cifsfs.h b/fs/cifs/cifsfs.h index d82f5fb..d6f0a7d 100644 --- a/fs/cifs/cifsfs.h +++ b/fs/cifs/cifsfs.h @@ -110,6 +110,9 @@ extern ssize_t cifs_getxattr(struct dentry *, const char *, void *, size_t); extern ssize_t cifs_listxattr(struct dentry *, char *, size_t); extern long cifs_ioctl(struct file *filep, unsigned int cmd, unsigned long arg); +struct sockaddr; +extern bool cifs_addr_is_specified(struct sockaddr *srcaddr); + #ifdef CONFIG_CIFS_EXPERIMENTAL extern const struct export_operations cifs_export_ops; #endif /* EXPERIMENTAL */ diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index c9d0cfc..784fd4a 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -157,6 +157,7 @@ struct TCP_Server_Info { struct sockaddr_in sockAddr; struct sockaddr_in6 sockAddr6; } addr; + struct sockaddr_storage srcaddr; /* locally bind to this IP */ wait_queue_head_t response_q; wait_queue_head_t request_q; /* if more than maxmpx to srvr must block*/ struct list_head pending_mid_q; diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index ec0ea4a..c70f6f8 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -49,6 +49,7 @@ #include "rfc1002pdu.h" #include "cn_cifs.h" #include "fscache.h" +#include "cifsfs.h" #define CIFS_PORT 445 #define RFC1001_PORT 139 @@ -105,6 +106,7 @@ struct smb_vol { bool sockopt_tcp_nodelay:1; unsigned short int port; char *prepath; + struct sockaddr_storage srcaddr; /* allow binding to a local IP */ struct nls_table *local_nls; }; @@ -1064,6 +1066,22 @@ cifs_parse_mount_options(char *options, const char *devname, "long\n"); return 1; } + } else if (strnicmp(data, "srcaddr", 8) == 0) { + vol->srcaddr.ss_family = AF_UNSPEC; + + if (!value || !*value) { + printk(KERN_WARNING "CIFS: srcaddr value" + " not specified.\n"); + return 1; /* needs_arg; */ + } + i = cifs_convert_address((struct sockaddr *)&vol->srcaddr, + value, strlen(value)); + if (i < 0) { + printk(KERN_WARNING "CIFS: Could not parse" + " srcaddr: %s\n", + value); + return 1; + } } else if (strnicmp(data, "prefixpath", 10) == 0) { if (!value || !*value) { printk(KERN_WARNING @@ -1392,8 +1410,42 @@ cifs_parse_mount_options(char *options, const char *devname, return 0; } +/** Returns true if srcaddr isn't specified and rhs isn't + * specified, or if srcaddr is specified and + * matches the IP address of the rhs argument. + */ +static bool +srcip_matches(struct sockaddr *srcaddr, struct sockaddr *rhs) +{ + if (cifs_addr_is_specified(srcaddr)) { + struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr; + struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr; + struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs; + struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)&rhs; + + switch (srcaddr->sa_family) { + case AF_INET: + if (saddr4->sin_addr.s_addr != vaddr4->sin_addr.s_addr) + return false; + break; + case AF_INET6: + if (!ipv6_addr_equal(&saddr6->sin6_addr, + &vaddr6->sin6_addr)) + return false; + break; + default: + return false; + } + return true; + } + else + return !cifs_addr_is_specified(rhs); +} + + static bool -match_address(struct TCP_Server_Info *server, struct sockaddr *addr) +match_address(struct TCP_Server_Info *server, struct sockaddr *addr, + struct sockaddr *srcaddr) { struct sockaddr_in *addr4 = (struct sockaddr_in *)addr; struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr; @@ -1420,6 +1472,9 @@ match_address(struct TCP_Server_Info *server, struct sockaddr *addr) break; } + if (!srcip_matches(srcaddr, (struct sockaddr *)&server->srcaddr)) + return false; + return true; } @@ -1487,7 +1542,8 @@ cifs_find_tcp_session(struct sockaddr *addr, struct smb_vol *vol) if (server->tcpStatus == CifsNew) continue; - if (!match_address(server, addr)) + if (!match_address(server, addr, + (struct sockaddr *)&vol->srcaddr)) continue; if (!match_security(server, vol)) @@ -1602,6 +1658,8 @@ cifs_get_tcp_session(struct smb_vol *volume_info) * no need to spinlock this init of tcpStatus or srv_count */ tcp_ses->tcpStatus = CifsNew; + memcpy(&tcp_ses->srcaddr, &volume_info->srcaddr, + sizeof(tcp_ses->srcaddr)); ++tcp_ses->srv_count; if (addr.ss_family == AF_INET6) { @@ -2026,6 +2084,33 @@ static void rfc1002mangle(char *target, char *source, unsigned int length) } +static int +bind_socket(struct TCP_Server_Info *server) +{ + int rc = 0; + if (cifs_addr_is_specified((struct sockaddr *)&server->srcaddr)) { + /* Bind to the local IP address if specified */ + struct socket *socket = server->ssocket; + rc = socket->ops->bind(socket, + (struct sockaddr *) &server->srcaddr, + sizeof(server->srcaddr)); + if (rc < 0) { + struct sockaddr_in *saddr4; + struct sockaddr_in6 *saddr6; + saddr4 = (struct sockaddr_in *)&server->srcaddr; + saddr6 = (struct sockaddr_in6 *)&server->srcaddr; + if (saddr6->sin6_family == AF_INET6) + printk(KERN_WARNING "cifs: " + "Failed to bind to: %pI6c, error: %d\n", + &saddr6->sin6_addr, rc); + else + printk(KERN_WARNING "cifs: " + "Failed to bind to: %pI4, error: %d\n", + &saddr4->sin_addr.s_addr, rc); + } + } + return rc; +} static int ipv4_connect(struct TCP_Server_Info *server) @@ -2051,6 +2136,8 @@ ipv4_connect(struct TCP_Server_Info *server) cifs_reclassify_socket4(socket); } + bind_socket(server); + /* user overrode default port */ if (server->addr.sockAddr.sin_port) { rc = socket->ops->connect(socket, (struct sockaddr *) @@ -2213,6 +2300,8 @@ ipv6_connect(struct TCP_Server_Info *server) cifs_reclassify_socket6(socket); } + bind_socket(server); + /* user overrode default port */ if (server->addr.sockAddr6.sin6_port) { rc = socket->ops->connect(socket, -- 1.6.2.5 -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
